Download 3.8 The Circulatory System

3.2 The Circulatory System
The Circulatory System
Circulatory System is responsible for
transporting substances throughout
the body.
 This is the organ system made up of
the heart, blood vessels, and blood.
The Circulatory System Video:
http://www.youtube.com/watch?feature=pl
ayer_embedded&v=D3ZDJgFDdk0
Circulatory
System is
responsible
for
transporting
substances
throughout
the body.
Blood

Blood is a type of connective tissue made
up of 4 parts:
1. Red
blood cells
2. White
blood cells
3. Platelets
4. Plasma
1. Red Blood Cells
What it
Description
looks like
Red blood cells
make up half of
the blood by
volume.
They are bright
red and lack a
nuclei.
Function/Role
Contain
hemoglobin, a
protein that
picks up oxygen
and carbon
dioxide.
2. White Blood Cells
What it
Description
looks like
White blood
cells make up
half only 1% of
blood by
volume.
Function/Role
Fight and
destroy disease
causing bacteria
and viruses.
3. Platelets
What it
Description
looks like
Platelets make
up less than 1%
of blood by
volume.
Function/Role
Small cells that
help blood clot,
seal wounds
and stop
bleeding.
4. Plasma
What it
Description
looks like
Plasmas is the
protein-rich
liquid in which
blood cells float.
It makes up half
of the blood by
volume.
Function/Role
Carries blood
cells, dissolved
wastes,
nutrients and
hormones.
VIDEO: Blood Component Processing
http://www.youtube.com/watch?v=YMTtS2BbehI
The Heart

The heart is organized into 4 chambers:
2 upper chambers and 2 lower chambers

The human heart takes blood in from the lungs (the upper
chambers) and pumps it throughout the body (the lower
chambers).

Heart muscles are controlled by pacemaker cells which send
out an electrical signals telling them when to contract.

When resting, heart beats 50-100 times per minute.

During physical activity, your body needs more oxygen and
your heart beats faster.
The upper
chambers of
the heart take
in blood from
the body and
the lungs.
The lower
chambers
pump it into
the lungs or to
the rest of the
body to supply
oxygen to our
cells.
Blood Vessels
Blood vessels make up a network of tubes
that carry blood through the body.
3 types of blood vessels:
1)
Arteries – large muscular vessels that carry blood
away from the heart under pressure. Thick
muscular walls.
2)
Veins – large vessel that carries blood toward the
heart under low pressure.
3)
Capillaries – tiny thin-walled vessel that allow
the exchange of gases, nutrients, and wastes
between the blood and body tissues.
The Circulation of Blood
• The blood flows through the circulatory
system in a closed pathway similar to the
figure 8.
• The pathway passes through the heart 2
times: once through the left side and then
once the right side.
The blood
flows
through
the
circulatory
system in
a closed
pathway
similar to
the figure
8.
Pathway of Blood
RIGHT SIDE = pumps blood to lungs.
LEFT SIDE = blood moves from lungs to heart
Blood pumps to lungs and gas exchange takes
place in the lungs:
blood absorbs oxygen and gives
off carbon dioxide.
Oxygen-rich blood then travels back from the
lungs into the left side of the heart.
Pathway of Blood (cont.)
• The heart then pumps the blood to the rest of
the body through the arteries.
• The arteries then divide into smaller vessels and
then even smaller capillaries.
• From the capillaries, oxygen and other
substances diffuse out of the blood into
surrounding tissues into the blood.
• The blood then flows from the capillaries into
the veins.
• It completes the circuit returning to the right
side of the heart.
Pumping Blood
https://www.youtube.com/watch?v=JA0Wb
3gc4mE
 Homework 